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Researchers at INFN Pisa are currently developing a detector based on MICROMEGAS technology, sensitive to atoms with a kinetic energy in the 1–100 keV range and operating under low-pressure conditions (100 hPa or less). For the detector test, an Ion Beam Facility (IBF) was set up at the INFN laboratory in Pisa in order to have a controlled test bench capable of guaranteeing the stability and repeatability of the measurements. The group effort dedicated to the development of the IBF led to detailed characterization measurements of the MICROMEGAS performance using H 2 and He ion beams. [ABSTRACT FROM AUTHOR]

In the last decades, interest has grown in the development of detectors that can accurately measure energy and track of low-energy (1–100 keV) charged particles. In this paper we present our effort to construct a resistive MICROMEGAS detector with a wide amplification gap (192 μm), to achieve high gain with a low discharge probability, even when operating with a low-pressure gas down to 50 mbar. The detector response (gain, energy resolution, relative primary charge collection efficiency) to X-rays from a 55Fe source was measured under different operating conditions of amplification and drift fields, gas pressure and gas mixture composition. The results obtained and their temporal stability demonstrate that the detector can be used for the measurement of low-energy radiation with good energy resolution. [ABSTRACT FROM AUTHOR]

Abstract: In future collider experiments the increasing luminosity and center of mass energy are rising challenges in the research field of tracking systems where it is crucial to have very fast sensors with efficient readout in order to sustain the high particle flux. In this context we propose a high-efficiency digital readout architecture for large binary pixel matrices that is meant to cope with high hit-rates, up to 100MHz/cm2, foreseen in the innermost tracker layer of the new generation particle accelerators. We modelled and designed several readout circuits to be integrated in the periphery of hybrid detectors. In this work we focus on a particular solution, to be interconnected to a matrix covering an area of 1.3cm2. The hits are latched at pixel level, and the matrix provides a digital interface to the peripheral digital readout. The architecture is highly paralleled in order to reduce the pixels dead time introduced by readout which can be operated in data-push or triggered mode. In addition, a cluster compression algorithm, exploiting also the time sorted hit extraction, has been developed to reduce the output bandwidth. The architecture has been modelled in a hardware description language, to be synthesized in a net-list of foundry standard-cells. A Monte Carlo hit generator has been attached to simulations to evaluate the readout efficiency, both in data-push and triggered working mode. Simulation results will be presented, pointing out beside the efficiency results, the benefits introduced by the compression algorithm. [Copyright &y& Elsevier]

A prototype of a Focused Internal Reflection Cherenkov, equipped with 16 arrays of NUV-SiPM, was tested at CERN SPS in March 2015 with beams of relativistic ions at 13, 19 and 30 GeV/n obtained from fragmentation of an Ar primary beam. The detector, designed to identify cosmic nuclei, features a Fused Silica radiator bar optically connected to a cylindrical mirror of the same material and an imaging focal plane of dimensions ∼4 cm×3 cm covered with a total of 1024 SiPM photosensors. Thanks to the outstanding performance of the SiPM arrays, the detector could be operated in photon counting mode as a fully digital device. The Cherenkov pattern was recorded together with the total number of detected photoelectrons increasing as Z 2 as a function of the atomic number Z of the beam particle. In this paper, we report on the characterization and test of the SiPM arrays and the performance of the Cherenkov prototype for the charge identification of the beam particles. [ABSTRACT FROM AUTHOR]

In this paper, we present the implementation and preliminary evaluation of a new type of silicon sensor for charged particle detection operated in Geiger-mode. The proposed device, formed by two vertically-aligned pixel arrays, exploits the coincidence between two simultaneous avalanche events to discriminate between particle-triggered detections and dark counts. A proof-of-concept two-layer sensor with per-pixel coincidence circuits was designed and fabricated in a 150 nm CMOS process and vertically integrated through bump bonding. The sensor includes a 48×16 pixel array with 50 μ m × 75 μ m pixels. This work describes the sensor architecture and reports a selection of results from the characterization of the avalanche detectors in the two layers. Detectors with an active area of 43 × 45 μ m 2 have a median dark count rate of 3 kHz at 3.3 V excess bias and a breakdown voltage non-uniformity lower than 20 mV. [ABSTRACT FROM AUTHOR]

Using a bulk Micro-Megas (MM) detector an energy measurement can be obtained collecting the total charge reaching the mesh electrode connected to a low noise charge sensitive preamplifier. When operating such a device in a low-pressure gas regime, it is necessary to modify the amplification gap geometry to reach the optimal detector gain. This implies changes in the input capacitance of the preamplifier influencing its signal to noise ratio and thus the detector energy resolution. An ad-hoc high-gain and low-noise charge preamplifier has been developed to cope with the requirements of our application field. In this short report, we present the development activities focused to the study of a configurable charge amplifier to be connected to a MM detector having different mesh capacitances. [ABSTRACT FROM AUTHOR]

Within the family of the Micro Strip Gas Detectors (MSGD), the intrinsic characteristics of the bulk Micro-Megas (MM) device represent the most promising features for the construction of a new instrument to be operated as a TPC gas chamber in a low-pressure regime. In this study, we present the main properties of a low-pressure bulk MM detector in which the amplification gap was slightly increased to improve the gas gain. Two configurations have been deeply studied: the first one with a gap of 128 μ m and a second one with a 192 μ m gap, both filled and operated with a gas mixture (Ar-CO 2) at pressures below 100 mbar. The dependence of the gain and the energy resolution on the amplification field, gas pressure and drift field have been evaluated. The reliability of the measured performance, combined with the simple and robust structure of the detector even with an increased length of amplification gap, make it an attractive choice for applications where the track length of low energy particles is detected by using a low-pressure filling gas. [ABSTRACT FROM AUTHOR]

A readout channel for applications to X-ray diffraction imaging at free electron lasers has been developed in a 65 nm CMOS technology. The analog front-end circuit can achieve an input dynamic range of 100 dB by leveraging a novel signal compression technique based on the non-linear features of MOS capacitors. Trapezoidal shaping is accomplished through a transconductor and a switched capacitor circuit, performing gated integration and correlated double sampling. A small area, low power 10 bit successive approximation register (SAR) ADC, operated in a time-interleaved fashion, is used for numerical conversion of the amplitude measurement. Operation at 5 MHz of the analog channel including the shaper was demonstrated. Also, the channel was found to be compliant with single 1 keV photon resolution at 1.25 MHz. The ADC provides a signal-to-noise ratio (SNR) of 56 dB, corresponding to an equivalent number of bits (ENOB) of 9 bits, and a differential non linearity DNL < 1 LSB at a sampling rate slightly larger than 1.8 MHz. [ABSTRACT FROM AUTHOR]

The INFN PixFEL project is developing the fundamental building blocks for a large area X-ray imaging camera to be deployed at next generation free electron laser (FEL) facilities with unprecedented intensity. Improvement in performance beyond the state of art in imaging instrumentation will be explored adopting advanced technologies like active edge sensors, a 65 nm node CMOS process and vertical integration. These are the key ingredients of the PixFEL project to realize a seamless large area focal plane instrument composed by a matrix of multilayer four-side buttable tiles. In order to minimize the dead area and reduce ambiguities in image reconstruction, a fine pitch active edge thick sensor is being optimized to cope with very high intensity photon flux, up to 10 4 photons per pixel, in the range from 1 to 10 keV. A low noise analog front-end channel with this wide dynamic range and a novel dynamic compression feature, together with a low power 10 bit analog to digital conversion up to 5 MHz, has been realized in a 110 μm pitch with a 65 nm CMOS process. Vertical interconnection of two CMOS tiers will be also explored in the future to build a four-side buttable readout chip with high density memories. In the long run the objective of the PixFEL project is to build a flexible X-ray imaging camera for operation both in burst mode, like at the European X-FEL, or in continuous mode with the high frame rates anticipated for future FEL facilities. [ABSTRACT FROM AUTHOR]

A prototype of an Internal Reflection Cherenkov, equipped with a SiO 2 (fused silica) radiator bar optically connected to a cylindrical mirror, was tested at CERN SPS in March 2015 with a beam of relativistic ions obtained from fragmentation of primary argon nuclei at energies 13, 19 and 30 GeV/n. The detector, designed to identify cosmic nuclei, features an imaging focal plane of dimensions ~ 4 cm × 3 cm equipped with 16 arrays of NUV-SiPM (near-ultraviolet sensitive silicon photon avalanche detector) for a total of 1024 sensitive elements. The outstanding performance of the photodetectors (with negligible background in between adjacent photopeaks) allowed us to apply the technique of photon counting to the Cherenkov light collected on the focal plane. Thanks to the fine granularity of the array elements, the Cherenkov pattern was recorded together with the total number of detected photoelectrons increasing as Z 2 as a function of the atomic number Z . In this paper, we report the performance of the SiPM arrays and the excellent resolution achieved by the digital Cherenkov prototype in the charge identification of the elements present in the beam. [ABSTRACT FROM AUTHOR]

The PixFEL project is conceived as the first stage of a long term research program aiming at the development of advanced X-ray imaging instrumentation for applications at the free electron laser (FEL) facilities. The project aims at substantially advancing the state-of-the-art in the field of 2D X-ray imaging by exploring cutting-edge solutions for sensor development, for integration processes and for readout channel architectures. The main focus is on the development of the fundamental microelectronic building blocks for detector readout and on the technologies for the assembly of a multilayer module with minimum dead area. This work serves the purpose of introducing the main features of the project, together with the simulation results leading to the first prototyping run. [ABSTRACT FROM AUTHOR]

Abstract: Monolithic active pixel sensors fabricated in a bulk CMOS technology with no epitaxial layer and standard resistivity ( ) substrate, featuring a deep N-well as the collecting electrode (DNW MAPS), have been exposed to , up to a final dose of 10Mrad (SiO2), and to neutrons from a nuclear reactor, up to a total 1MeV neutron equivalent fluence of about . The irradiation campaign was aimed at studying the effects of radiation on the most significant parameters of the front-end electronics and on the charge collection properties of the sensors. Device characterization has been carried out before and after irradiations. The DNW MAPS irradiated with 60Co were also subjected to high temperature annealing (100°C for 168h). Measurements have been performed through a number of different techniques, including electrical characterization of the front-end electronics and of DNW diodes, laser stimulation of the sensors and tests with 55Fe and 90Sr radioactive sources. This paper reviews the measurement results, their relation with the damage mechanisms underlying performance degradation and provides a new comparison between DNW devices and MAPS fabricated in a CMOS process with high resistivity ( ) epitaxial layer. [Copyright &y& Elsevier]

Abstract: The high luminosity SuperB asymmetric collider, to be built near the INFN National Frascati Laboratory in Italy, has been designed to deliver a luminosity greater than 1036 cm−2 s−1 with moderate beam currents and a reduced center of mass boost with respect to earlier B-Factories. An improved vertex resolution is required for precise time-dependent measurements and the SuperB Silicon Vertex Tracker will be equipped with an innermost layer of small radius (about 1.5cm), resolution of in both coordinates, low material budget ( X0), and able to withstand a background rate of several tens of MHz/cm2. The ambitious goal of designing a thin pixel device with these stringent requirements is being pursued with specific R&D programs on different technologies: hybrid pixels, CMOS MAPS and pixel sensors developed with vertical integration technology. The latest results on the various pixel options for the SuperB SVT will be presented. [Copyright &y& Elsevier]

For the phase II of MEG, we are going to develop a combined trigger and DAQ system. Here we focus on the former side, which operates an on-line reconstruction of detector signals and event selection within 450 μs from event occurrence. Trigger concentrator boards (TCB) are under development to gather data from different crates, each connected to a set of detector channels, to accomplish higher-level algorithms to issue a trigger in the case of a candidate signal event. We describe the major features of the new system, in comparison with phase I, as well as its performances in terms of selection efficiency and background rejection. [ABSTRACT FROM AUTHOR]

This work presents the design of an interleaved Successive Approximation Register (SAR) ADC, part of the readout channel for the PixFEL detector. The PixFEL project aims at substantially advancing the state-of-the-art in the field of 2D X-ray imaging for applications at the next generation Free Electron Laser (FEL) facilities. For this purpose, the collaboration is developing the fundamental microelectronic building blocks for the readout channel. This work focuses on the design of the ADC carried out in a 65 nm CMOS technology. To obtain a good tradeoff between power consumption, conversion speed and area occupation, an interleaved SAR ADC architecture was adopted. [ABSTRACT FROM AUTHOR]

Abstract: A prototype of a mixed-mode ASIC composed of a fast readout architecture that interfaces with a matrix of 4096 Monolithic Active Pixel Sensor (MAPS) was fabricated via STM 130nm CMOS technology. Groups of 4×4 pixels form a macro-pixel (MP). The readout architecture is parallel and could overcome the readout speed limit of big matrices. As the output port can only accept one-hit information at a time, an internal queuing system has been provided to face high hit-rate conditions. The ASIC can work in two different manners as it can be connected to an actual full-custom matrix of MAPS or to a digital matrix emulator composed of standard cells, for testing facilities. For both operating modes a slow-control phase is required to load the chip configuration. Previous versions of similar ASICs were designed and tested. The work is aimed at improving the design of MAPS detectors with an on-chip fast sparsification system, for particle tracking, to match the requirements of future high-energy physics experiments. The readout architecture implemented is data driven extending the flexibility of the system to be also used in first level triggers on tracks in vertex detectors. Preliminary simulations and tests indicate that the readout system can cope with an average hit-rate up to 100MHz/cm2 if a master clock of 80MHz is used, while maintaining an overall efficiency over 99%. [Copyright &y& Elsevier]

Abstract: Solid-state photodetectors working in the Geiger mode—known as Silicon PhotoMultipliers (SiPM) or MultiPixel Photon Counters (MPPC)—are currently being developed with increasingly large active areas. Potential applications for low-light-level detection were investigated with a MPPC, recently made available by Hamamatsu. The device was optically coupled with a scintillator and its performances, in terms of single photoelectron discrimination, were studied in a series of measurements under different operating conditions. An active control of the gain was implemented by a linear feedback on the operating voltage. The results of the tests are discussed. [Copyright &y& Elsevier]

Abstract: Silicon photo-multipliers (SiPM) consist in matrices of tiny, passive quenched avalanche photo-diode cells connected in parallel via integrated resistors and operated in Geiger mode. Novel types of SiPM are being developed at FBK-IRST (Trento, Italy). Despite their classical shallow junction n-on-p structure the devices are unique in their enhanced photo-detection efficiency (PDE) for short-wavelengths and in their low level of dark rate and excess noise factor. After a summary of the extensive SiPM characterization we will focus on the study of PDE and the single photon timing resolution. [Copyright &y& Elsevier]

Abstract: Positron Emission Tomography (PET) for small animal studies requires high-resolution gamma cameras with high sensitivity. Traditionally, inorganic scintillators are used and, in recent times, coupled to position sensitive PMTs to achieve a higher resolution. Such PSPMTs are costly, operated at high voltage and have a relatively low packing fraction. However, their advantage, compared to current solid state photodetectors, is their high signal-to-noise ratio. The Silicon Photomultiplier (SiPM) is a silicon diode detector that shows great promise as a photodetector for scintillators and hence application in nuclear medicine imaging applications. The microcell MRS (Metal–Resistor–Semiconductor) structure of the SiPM leads to a self-quenching, Geiger-mode avalanche photodiode (GAPD), that produces a large gain at low bias voltage (50V) and proportional output for moderate photon flux. Such a compact silicon detector, with a performance similar to a PMT, is obviously well disposed to being developed into a close-packed array in order to have a position-sensitive detection surface. We propose a miniature, high-resolution camera for a small-animal PET imaging system that is based on such an array of SiPM. The design is based upon the classic Anger camera principle; each detector module consists of a continuous slab of scintillator, viewed by a matrix of SiPM. A detector head of in area is proposed, constructed from three such modules of the continuous camera described above. The stacked layers would give the system intrinsic depth of interaction (DOI) information. A summary of measured SiPM performance and results of a simulation of the proposed camera, using the Monte Carlo package GEANT4, are presented. It is shown that using three layers of 5mm thick LSO, gives an efficiency of 68% with maximum count rates in the front layers. Intrinsic spatial resolution of FWHM was found although this is degraded at the edges. Although the inclusion of DOI information increases the overall spatial resolution, the parallax error was still found to be the limiting factor in a small animal system. [Copyright &y& Elsevier]

Abstract: By exploiting the triple-well option available in a deep-submicron CMOS process, we developed monolithic active pixel sensors (MAPS) with the unique features of full analog signal processing and digital functionality implemented at the pixel level. After briefly reviewing the results achieved with the first prototype chip, we report on the extensive measurements on the second prototype, containing both single-channel sensors, with an improved noise figure, and an pixel array. For the pixel having a collecting electrode area of we measured an equivalent noise charge of about 40 electrons. Using the 5.9keV line, we obtained a Signal-to-noise (S/N) ratio of about 30. The pixel matrix has been successfully readout up to 30MHz. Through noise scans, an expected significant threshold dispersion has been measured. The measurements presented in this paper confirm the capability of our MAPS, based on the deep n-well concept, to be operated as ionizing radiation detectors and suggest a series of improvements we are already implementing in the design of the next prototype chip. [Copyright &y& Elsevier]

Abstract: We present a new approach to the design of monolithic active pixel sensors (MAPS) in CMOS technology. By exploiting the triple well option, available in modern deep-submicron processes, it was possible to implement at the pixel level a full analog signal processor and to increase the area of the sensing electrode. These two new features aim to address some limiting aspects of conventional MAPS, such as the read-out speed and the charge collection efficiency. We report on the characterization of the first prototype chip, in particular the calibration with soft X-rays and the response to -rays, demonstrating the capability of the sensor in detecting ionizing radiation. [Copyright &y& Elsevier]

Abstract: This work studies the feasibility of a new implementation of CMOS monolithic active pixel sensors (MAPS) for applications to charged particle tracking. As compared to standard three MOSFET MAPS, where the charge signal is readout by a source follower, the proposed front-end scheme relies upon a charge sensitive amplifier (CSA), embedded in the elementary pixel cell, to perform charge-to-voltage conversion. The area required for the integration of the front-end electronics is mostly provided by the collecting electrode, which consists of a deep n-type diffusion, available as a shielding frame for n-channel devices in deep submicron, triple well CMOS technologies. Based on the above concept, a chip, which includes several test structures differing in the sensitive element area, has been fabricated in a CMOS process. In this paper, the criteria underlying the design of the pixel level analog processor will be presented, together with some preliminary experimental results demonstrating the feasibility of the proposed approach. [Copyright &y& Elsevier]

Abstract: The Silicon PhotoMultiplier (SiPM) APD represents an interesting advance in photodetection and could soon be a rival to traditional PMTs in many applications. The SiPM is effectively a densely packed 2D array of Geiger-mode APD microcells, each having individual resistive quenching and multiplexed outputs. In this way the SiPM acts as a linear, high-gain photodetector for moderate photon flux . The Metal-Resistor-Silicon (MRS) structure SiPM, produced by CPTA Russia, has been characterised and tested for scintillator light detection in medical applications such as PET. We present a summary of measurements of the device''s primary operating characteristics and results of the application to scintillator readout. [Copyright &y& Elsevier]

Abstract: We designed and fabricated a novel monolithic active pixel sensor (MAPS), in STMicrolectronics CMOS technology, exploiting the triple well option to implement, at the pixel level, a more complex signal processor and to increase the size of the charge collecting electrode with respect to previously developed CMOS MAPS. This was possible using the deep n-well, available in triple well technology, as a sensing electrode and placing, in the same physical area, part of the readout electronics. The signal processing chain, implemented in the elementary cell, includes a low noise charge preamplifier, a shaper, a discriminator and a latch. The first prototype chips have been successfully tested with very encouraging results. In this work we present the performance of the front-end electronics and the response of the sensor to ionizing radiation. [Copyright &y& Elsevier]

Abstract: Cosmic Ray Energetics And Mass (CREAM) is a balloon-borne experiment designed to perform direct measurements of cosmic ray composition over the elemental range from proton to iron to the supernova energy scale of in a series of balloon flights using the new Ultra Long Duration Balloon (ULDB) capability under development by NASA. The first flight of CREAM will take place at the end of 2004 from Antarctica. The instrument includes a sampling tungsten/scintillating fiber calorimeter preceded by a graphite target with scintillating fiber hodoscopes, a pixelated silicon charge detector, a transition radiation detector and a segmented timing-based particle-charge detector. The thin ionization calorimeter has been designed to operate in the range of energies from a few hundred GeV to 1PeV providing imaging capability in the reconstruction of the showers originating from the interaction of primary nuclei in the carbon target. A twin calorimeter for the second CREAM payload has been built and tested at CERN. Its construction technique and preliminary test results are presented. [Copyright &y& Elsevier]

Real time pattern recognition is becoming a key issue in many position sensitive detector applications. The CDF collaboration is building SVT: a specialized electronic device designed to perform real time track reconstruction using the Silicon VerteX detector (SVX II). This will strongly improve the CDF capability of triggering on events containing b quarks, usually characterized by the presence of a secondary vertex.SVT is designed to reconstruct in real time charged particles trajectories using data coming from the silicon vertex detector and the central outer tracker drift chamber. The SVT architecture and algorithm have been specially tuned to minimize processing time without degrading parameter resolution. [Copyright &y& Elsevier]

An array of Single Photon Avalanche Diodes (SPAD), fabricated in a 180 nm CMOS technology featuring a high voltage (HV) option, has been investigated in terms of radiation tolerance, in view of the design of low material budget dual-tier detectors for charged particle tracking based on the coincidence of signals coming from pairs of vertically aligned pixels. Each pixel in the array includes both the processing electronics and the sensing element in a monolithic structure. The test vehicles were irradiated with 10 keV X-rays up to a dose of 1 Mrad (SiO 2) and with neutrons up to a fluence of 1011 n e q cm−2. A selection of the characterization results are presented together with the main features of a new large scale SPAD array to be fabricated in a 150 nm CMOS technology and ready for vertical interconnection in a dual layer structure. • Characterization of SPADs in a 180 nm CMOS technology. • Radiation tolerance evaluation involving ionizing and non-ionizing sources. • Design features of a new charged particle detector based on 150 nm CMOS SPADs in a dual-layer structure. [ABSTRACT FROM AUTHOR]

In the framework of the upgrade of the MEG experiment a new trigger system with demanding performances in terms of latency was designed. To achieve the goal of 512 ns latency the serial connections between trigger boards have been optimized so that they only rely on serial to parallel shift registers for the data flow, minimizing the amount of logic to be crossed by data. A dedicated Finite State Machine (FSM) was designed to select the sampling point of the serial stream with respect to an external precision clock used by both transmitter and receiver. As a proof of concept a 16 000 channel weighted waveform sum including pedestal suppression, was computed, resulting in 700 ns of latency. [ABSTRACT FROM AUTHOR]

The WaveDAQ is a full custom, compact and highly integrated trigger and data acquisition system. Despite the decisive urge from the MEG II experiment at PSI aiming at a sensitivity of 6 × 1 0 − 14 on the μ → e γ decay, it is a general purpose device suited for small and medium-sized applications in the range from 16 to about 10 000 channels. It exploits the performance of the DRS4 waveform digitiser with a sampling speed programmable from 1 to 5 GSPS; each input channel can supply HV to arrays of SiPMs and provides a front-end amplification with gains chain in the range from 0.5 up to 100 and GHz bandwidth. Input signals are, in parallel to the DRS4, digitised at 80 MSPS and used in an FPGA-based trigger; fast discriminators associated to each input channel are also used for online reconstruction. This paper presents the WaveDAQ design principles and the results obtained by a demonstrator in the MEG II pre-engineering run in fall 2017 with a homogeneous LXe detector and a plastic scintillation detector both readout by SiPMs and in the tests associated to the Δ E-TOF prototype of the FOOT detector. [ABSTRACT FROM AUTHOR]

Abstract: The chip prototype Apsel4well, including monolithic active pixel sensors (MAPS), is meant as an upgrade solution for the Layer0 of the SuperB silicon vertex tracker. The design is based on a 180nm CMOS process with quadruple well called INMAPS. This technology makes it possible to overcome the main drawbacks of three transistor MAPS. Moreover, the presence of a high resistivity epitaxial layer is expected to lead to a further improvement in terms of charge collection performance and radiation resistance. This work introduces the channel readout design features of the chip Apsel4well developed with the mentioned approach and shows results of device simulations of a 3×3 pixel matrix. [Copyright &y& Elsevier]

Abstract: A battery-powered, wireless Radon sensor has been designed and realized using a BJT, fabricated on a high-resistivity-silicon substrate, as a radiation detector. Radon daughters are electrostatically collected on the detector surface. Thanks to the BJT internal amplification, real-time α particle detection is possible using simple readout electronics, which records the particle arrival time and charge. Functional tests at known Radon concentrations, demonstrated a sensitivity up to 4.9cph/(100Bq/m3) and a count rate of 0.05cph at nominally-zero Radon concentration. [Copyright &y& Elsevier]

Abstract: We report on recent beam test results for the APSEL4D chip, a new deep n-well MAPS prototype with a full in-pixel signal processing chain obtained by exploiting the triple well option of the CMOS process. The APSEL4D chip consists of a 4096 pixel matrix (32 rows and 128 columns) with pixel cell area, with custom readout architecture capable of performing data sparsification at pixel level. APSEL4D has been characterized in terms of charge collection efficiency and intrinsic spatial resolution under different conditions of discriminator threshold settings using a 12GeV/c proton beam in the T9 area of the CERN PS. We observe a maximum hit efficiency of 92% and we estimate an intrinsic resolution of about . The data driven approach of the tracking detector readout chips has been successfully used to demonstrate the possibility to build a Level 1 trigger system based on associative memories. The analysis of the beam test data is critically reviewed along with the characterization of the device under test. [ABSTRACT FROM AUTHOR]

Abstract: The SuperB asymmetric collider has been designed to deliver a luminosity greater than with moderate beam currents. Comparing to current B-Factories, the reduced center of mass boost of the SuperB machine requires improved vertex resolution to allow precision measurements sensitive to New Physics. We present the conceptual design of the silicon vertex tracker (SVT) for the SuperB detector with the present status of the R&D on the different options under study for its innermost Layer0. [Copyright &y& Elsevier]

Abstract: Space-based and balloon-borne experiments, designed for direct measurements of the elemental composition and energy spectra of charged cosmic rays, require an unambiguous identification of the incoming particle. This task can be carried out via an accurate determination of the charge of the primary nucleus by dE/dx measurements with pixelated silicon detectors. At energies close to the knee , the low values of the fluxes require large sensitive areas of a few . A prototype silicon detector with 64 pads (pixels of area) was developed on a wafer as a building block for a large area silicon array. Results on the characterization and performance of the detector are presented. [Copyright &y& Elsevier]

In this paper we present a position-sensitive detector based on the vertical integration of pairs of aligned pixels operating in Geiger-mode regime and designed for charged particle detection. This novel device exploits the coincidence between two simultaneous avalanche events to discriminate between particle-triggered detections and dark counts. This concept allows to have a reduced material budget and low power consumption in spite of a high granularity and fast timing response. A proof-of-principle prototype was designed and fabricated in a 150 nm CMOS process and vertically integrated through bump bonding. This first demonstrator has been characterized and tested with a high energy particle beams at CERN SPS/PS facilities, in different configurations, featuring a reduction of the dark-count rate (DCR) at room temperature from ∼ 100 kHz/mm 2 to about 24 Hz/mm 2 a particle detection efficiency limited only by the geometric factor. The device radiation tolerance has been investigated, via irradiation of single tiers with 10 keV X-rays up to a dose of 1 Mrad (SiO 2) and with neutrons up to a fluence of 1011 cm−2. A second prototype, addressing the goal to improve the present fill-factor, has been designed, manufactured and approaches now the characterization phase. Potential applications of this sensor include high spatial resolution tracking in high-energy experiments, radiation monitoring in space and radiation imaging in nuclear medicine. A small hand-held demonstrator is under construction for radio-guided surgery. [ABSTRACT FROM AUTHOR]

We report on the design and TCAD simulations of planar p-on-n sensors with active edge aimed at a four-side buttable X-ray detector module for future FEL applications. Edge terminations with different number of guard rings were designed to find the best trade-off between breakdown voltage and border gap size. The methodology of the sensor design, the optimization of the most relevant parameters to maximize the breakdown voltage and the final layout are described. [ABSTRACT FROM AUTHOR]

Abstract: The SuperB asymmetric e+e− collider, to be built near the INFN National Frascati Laboratory in Italy, has been designed to deliver a luminosity greater than 1036 cm−2 s−1 with moderate beam currents, allowing precision measurements in the flavour sector sensitive to New Physics. The conceptual design of the Silicon Vertex Tracker for the SuperB Detector is presented, based on double-sided silicon strip detectors for the outer layers, with the addition of an innermost Layer 0 close to the interaction point, with low material budget and capable of sustaining a background rate of several MHz/cm2. [Copyright &y& Elsevier]